Shortest Distance to Target String in a Circular Array — LeetCode 2515 Python Solution

The problem

You are given a 0-indexed circular string array words and a string target. A circular array means that the array's end connects to the array's beginning.

Example

Input

words = ["hello","i","am","leetcode","hello"], target = "hello", startIndex = 1

Output

1

Explanation

We start from index 1 and can reach "hello" by

Python solution

class Solution:
    def closetTarget(self, words: List[str], target: str, startIndex: int) -> int:
        n = len(words)
        ans = n
        for i, w in enumerate(words):
            if w == target:
                t = abs(i - startIndex)
                ans = min(ans, t, n - t)
        return -1 if ans == n else ans

Complexity

Pattern: Hash Map

Trade memory for time: remember what you have seen so the second pass never happens. LeetCode 2515. Shortest Distance to Target String in a Circular Array is filed here because the reference solution below belongs to the algorithm family this hub collects, even though its LeetCode tags point elsewhere.

The hash map guide has the Python template for the pattern and the 709 LeetCode problems that use it.

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